Battery pack

Abstract

To provide a battery pack in which the corrosion or direct influence of a high-temperature high-pressure material with respect to a bottom part protection plate is reduced and the risk of penetration of the bottom part protection plate is also reduced.SOLUTION: A battery pack includes a case and a cell assembly disposed in the case. The case includes a heat exchange plate 5 and a bottom plate protection plate 7 disposed under the heat exchange plate. Each cell assembly includes a plurality of cells. On one side of each cell that faces the heat exchange plate, an explosion-proof valve is disposed. On the heat exchange plate, a pressure relief penetration hole corresponding to the explosion-proof valve is disposed. Between the heat exchange plate and the bottom plate protection plate, a reinforcement member 6 is disposed. Each reinforcement member includes a base part disposed on the bottom part protection plate, and a support part connected to the base part and supported between the bottom part protection plate and the heat exchange plate. In a height direction of the battery pack, the projection of the pressure relief penetration hole overlaps with the projection of the base part at least partially.SELECTED DRAWING: Figure 11

Description

[Technical field]

[0001] The present invention relates to the technical field of energy storage devices, and more particularly to battery packs. [Background technology]

[0002] Generally, a battery pack includes a case and a cell assembly disposed in the case, and an explosion-proof valve is disposed in the cell of the cell assembly. When one cell undergoes thermal runaway, the internal pressure and temperature of the cell exceed the safety threshold of the explosion-proof valve, and the explosion-proof valve opens to release the pressure in the cell. The high-temperature and high-pressure material discharged from the explosion-proof valve needs to be released in a timely manner and discharged outside the case so as not to cause a chain reaction of thermal runaway of the surrounding cells and endanger the safety of the entire battery pack. Due to the requirements for lightweight and high energy density of the battery pack, the internal structures of the case, such as the bottom protective plate, are usually thin and light, and the properties of these structures, such as strength, impact resistance, and high temperature resistance, are poor. When the high-temperature and high-pressure material is discharged, if it comes into contact with the internal structures, such as the bottom protective plate of the case, these materials are likely to corrode the case, damaging the structure of the case or even penetrating the case, which may cause safety problems. Summary of the Invention [Problem to be solved by the invention]

[0003] In consideration of the above-mentioned shortcomings of the prior art, the present invention provides a battery pack that solves the problem of the prior art that the case is easily corroded by high temperature and pressure materials after the explosion-proof valve of the cell is opened. [Means for solving the problem]

[0004] In order to achieve the above and other related objects, the present invention provides a battery pack including a case and a cell assembly disposed within the case. The case includes a heat exchange plate and a bottom protective plate disposed below the heat exchange plate, and the cell assembly is disposed on the heat exchange plate. Each cell assembly includes a plurality of cells, and an explosion-proof valve is disposed on one side of each cell facing the heat exchange plate, and a pressure relief through hole corresponding to the explosion-proof valve is disposed on the heat exchange plate. A reinforcing member is disposed between the heat exchange plate and the bottom protective plate, and each reinforcing member includes a base portion and a support portion connected to the base portion. The base portion is disposed on the bottom protective plate, and the support portion is supported between the bottom protective plate and the heat exchange plate. In the height direction of the battery pack, a projection of the pressure relief through hole at least partially overlaps with a projection of the base portion.

[0005] Optionally, the pressure relief through holes are arranged in sequence in the width direction of the battery pack, and each base portion is an elongated strip extending in the width direction of the battery pack.

[0006] Optionally, each support is a long strip extending in the width direction of the battery pack, the support is disposed on either side of the base in the length direction of the battery pack, and each pressure release through hole is disposed between two support portions.

[0007] Optionally, a lifting portion extending in the width direction of the battery pack is further disposed on an edge of the support portion close to the heat exchange plate, and the lifting portion is attached to the heat exchange plate.

[0008] Optionally, lift sections are disposed on the two supports, the two lift sections extending away from each other.

[0009] Optionally, the included angle between the base and each support is an obtuse angle.

[0010] Optionally, the two lifting sections extend towards each other, and the lifting sections have receiving through-holes arranged therein that correspond to the pressure relief through-holes.

[0011] Optionally, the number of receiving through holes is less than the number of pressure relief through holes, and one of the receiving through holes is disposed corresponding to a plurality of the pressure relief through holes, or the number of receiving through holes corresponds to the number of the pressure relief through holes, and the receiving through holes and the pressure relief through holes are disposed in a one-to-one relationship.

[0012] Optionally, a plurality of cell assemblies are arranged, the cell assemblies being arranged in sequence in the length direction of the battery pack on the heat exchange plate, and a plurality of reinforcing members are arranged, the reinforcing members being arranged corresponding to the cell assemblies.

[0013] Optionally, on one side of the heat exchange plate remote from the bottom protective plate, there are disposed separation beams extending in the width direction of the battery pack, each separation beam being located between two adjacent cell assemblies.

[0014] Optionally, both ends of each separation beam are connected to the inner wall of the case, and a discharge through hole is arranged on the outer wall of the case corresponding to the end of the separation beam. A discharge passage communicating with the discharge through hole is arranged on the separation beam, and a communication through hole communicating with the discharge passage is arranged on the heat exchange plate corresponding to the separation beam. Heat exchange plate and bottom protection plate Between communicates with the discharge through hole via the communication through hole and the discharge path.

[0015] Optionally, each separation beam includes a top portion extending in a width direction of the battery pack, the top portion being located on the heat exchange plate and two side portions disposed on either side of the top portion toward the heat exchange plate, the side portions being connected onto the heat exchange plate and being surrounded by the heat exchange plate and the top portion to form a drainage passage.

[0016] Optionally, a waterproof moisture permeable valve is disposed in the exhaust through hole.

[0017] Optionally, in the height direction of the battery pack, a projection of the pressure relief through hole lies within a projection of the base portion.

[0018] Optionally, a protective layer is disposed on a side of the base portion facing the pressure relief through-hole and / or on a side of the support portion proximate the base portion.

[0019] Optionally, the protective layer comprises a mica plate.

[0020] Optionally, the reinforcing member is made of stainless steel.

[0021] Optionally, heat exchange channels are disposed within the heat exchange plates for circulating a heat exchange medium. Effect of the Invention

[0022] In summary, the battery pack provided by the present invention has the following advantages: The cell assemblies are disposed on the heat exchange plate, and each cell assembly includes a plurality of cells. The explosion-proof valves of the cells are all disposed on one side of the cells facing the heat exchange plate, and the heat exchange plate is disposed with pressure relief through-holes corresponding to the explosion-proof valves. In this way, when the explosion-proof valves of the cells are opened, the high-temperature and high-pressure material ejected from the explosion-proof valves can flow between the heat exchange plate and the bottom protective plate through the corresponding pressure relief holes for pressure relief. The reinforcing members are disposed between the heat exchange plate and the bottom protective plate, and each reinforcing member includes a base portion and a support portion connected to the base portion. The base portion is disposed on the bottom protective plate, and the support portion is supported between the bottom protective plate and the heat exchange plate. In the height direction of the battery pack, the projection of the pressure relief through-holes at least partially overlaps with the projection of the base portion. Thus, the reinforcing members support and reinforce the bottom protective plate and the heat exchange plate. Furthermore, after the high-temperature and high-pressure substance enters between the heat exchange plate and the bottom protection plate through the pressure relief through-hole, the high-temperature and high-pressure substance can be blocked by the overlapping portion of the projection of the base part of the reinforcing member and the projection of the pressure relief through-hole in the height direction of the battery pack, thus reducing the corrosion and direct impact of the high-temperature and high-pressure substance on the bottom protection plate and reducing the risk of the bottom protection plate being penetrated. [Brief description of the drawings]

[0023] [Figure 1] 1 is a schematic three-dimensional view showing the structure of a battery pack according to an embodiment of the present invention; [Diagram 2] 1 is a schematic three-dimensional view showing the structure of a case and cell assembly according to one embodiment of the present invention. [Diagram 3] FIG. 3 is a schematic top view of the structure of FIG. 2. [Figure 4] 2 is a schematic three-dimensional view showing the structure of a case according to an embodiment of the present invention. FIG. [Diagram 5] FIG. 2 is a schematic three-dimensional diagram showing the structure of one cell assembly according to one embodiment of the present invention. [Figure 6] FIG. 2 is a schematic exploded view showing the structure of a case according to an embodiment of the present invention. [Figure 7] FIG. 2 is a schematic three-dimensional view showing the structure of a heat exchange plate and a bottom protection plate according to an embodiment of the present invention. [Figure 8] FIG. 4 is a schematic cross-sectional view showing the AA cross-sectional structure of FIG. [Figure 9] FIG. 9 is a schematic enlarged view showing a part of the structure of FIG. 8. [Figure 10] FIG. 2 is a schematic cross-sectional view showing the structure of a through hole for night discharge in one embodiment of the present invention. [Figure 11] 4 is a schematic enlarged view showing a cross-sectional structure of a part of FIG. [Figure 12] 1 is a schematic cross-sectional view showing a structure of a separation beam according to an embodiment of the present invention. [Figure 13] 4 is a schematic enlarged view showing a local structure of a cross section CC of FIG. 3. [Figure 14] 1 is a first schematic diagram showing a structure of a reinforcing member according to an embodiment of the present invention; [Figure 15] FIG. 15 is a schematic enlarged view showing a local structure of FIG. [Figure 16] FIG. 4 is a second schematic diagram showing the structure of a reinforcing member according to an embodiment of the present invention. [Figure 17] FIG. 17 is a schematic enlarged view showing a part of the structure of FIG. 16. [Figure 18] FIG. 4 is a third schematic diagram showing the structure of a reinforcing member according to one embodiment of the present invention. [Figure 19] FIG. 19 is a schematic enlarged view showing a part of the structure of FIG. 18. [Figure 20] 1 is a schematic diagram showing an arrangement structure of a mica plate according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The implementation of the present invention is described below through specific embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the disclosure of this specification.

[0025] In addition, the structures, scales, dimensions, etc. shown in the accompanying drawings of this specification are merely used in conjunction with the contents disclosed in this specification so that a person skilled in the art can understand them. Since it is not intended to define the definition conditions for implementing the present invention, it has no technical significance. Any structural changes, changes in proportional relationships, or size adjustments without affecting the effects and purposes that can be achieved by the present invention are within the scope of the technical content disclosed in this specification. In addition, terms such as "upper", "lower", "left", "right", "middle", and "one side" cited in this specification are used only for convenience of explanation and are not used to limit the scope of the present invention. Cases in which the relative relationships are changed or adjusted without substantially changing the technical content are also included in the scope of application of the present invention.

[0026] 1 to 20, the present embodiment provides a battery pack 100 including a case 1 and a cell assembly 2 disposed in the case 1. The case 1 includes a heat exchange plate 5 and a bottom protective plate 7 disposed below the heat exchange plate 5, and the cell assembly 2 is disposed on the heat exchange plate 5.

[0027] The heat exchange plate 5 can exchange heat with the cell assembly 2 so that the cell assembly 2 is in an appropriate temperature range. This improves the working efficiency of the cell assembly 2 and reduces the risk of thermal runaway of the cell assembly 2. In some embodiments, the heat exchange plate 5 may be provided with a cooling structure such as a semiconductor cooling fin and a heating structure such as a heating fin, which can directly generate or absorb heat and exchange heat with the cell assembly 2. In this embodiment, a heat exchange flow path 53 for circulating a heat exchange medium is provided in the heat exchange plate 5. The heat exchange medium flows through the heat exchange flow path 53 and exchanges heat with the cell assembly 2 via the heat exchange plate 5.

[0028] As shown in Fig. 5, one cell assembly 2 includes a number of cells 20, and an explosion-proof valve 4 is disposed on one side of each cell 20 facing the heat exchange plate 5. In some embodiments, the cells 20 are cylindrical, and the cylindrical cells have the advantages of mature winding technology, high production efficiency, and low cost. In this embodiment, the cells 20 are square, and the square cells have the advantages of simple structure, easy arrangement, and high energy density.

[0029] 7 and 13, the heat exchange plate 5 is provided with pressure relief through holes 51 corresponding to the explosion-proof valves 4. When the explosion-proof valves 4 of the cells 20 are opened, the high-temperature and high-pressure material ejected from the explosion-proof valves 4 can flow between the heat exchange plate 5 and the bottom protection plate 7 through the corresponding pressure relief holes 51 for exhaust pressure. In this embodiment, the pressure relief through holes 51 are arranged between the adjacent heat exchange channels 53, for example, avoiding the heat exchange channels 53 in the heat exchange plate 5, to prevent leakage of the heat exchange medium in the heat exchange channels 53.

[0030] 1 and 5, in this embodiment, the battery pack 100 has a height direction, a width direction, and a length direction that are perpendicular to each other. The height direction of the battery pack 100 is the direction of the explosion-proof valve 4 on the cell 20, that is, the direction of the pressure release through-hole 51. The dimensions of the height direction, width direction, and length direction of the battery pack 100 are not limited.

[0031] 6, 7 and 11, reinforcing members 6 are disposed between the heat exchange plate 5 and the bottom protection plate 7, and each reinforcing member 6 includes a base portion 61 and a support portion 62 connected to the base portion 61. The base portion 61 is disposed on the bottom protection plate 7, and the support portion 62 is supported between the bottom protection plate 7 and the heat exchange plate 5. In the height direction of the battery pack 100, the projection of the pressure release through-hole 51 at least partially overlaps with the projection of the base portion 61.

[0032] The reinforcing member 6 supports and reinforces the bottom protection plate 7 and the heat exchange plate 5. After the high-temperature, high-pressure substance enters between the heat exchange plate 5 and the bottom protection plate 7 through the pressure release through hole 51, the high-temperature, high-pressure substance can be blocked by the overlapping portion of the projection of the base portion 61 of the reinforcing member 6 and the projection of the pressure release through hole 51 in the height direction of the battery pack 100. In this way, the corrosion and direct influence of the high-temperature, high-pressure substance on the bottom protection plate 7 is reduced, and the risk of the bottom protection plate 7 being penetrated is also reduced. In this embodiment, the projection of the pressure release through hole 51 is entirely within the projection of the base portion 61 in the height direction of the battery pack 100. When the high-temperature, high-pressure substance passes through the pressure release through hole 51 in the height direction of the battery pack 100, the high-temperature, high-pressure substance is all discharged onto the base portion 61. If the dimensions of the base portion 61 are the same, the effective protection area of ​​the base portion 61 in the bottom protection plate 7 can be increased, and the protection effect of the base portion 61 of the bottom protection plate 7 can be improved.

[0033] The heat exchange plate 5 and the reinforcing member 6 can be connected by laser penetration welding, rivet connection, adhesion, etc. The reinforcing member 6 and the bottom protection plate 7 can be connected by various methods such as laser penetration welding, adhesion, rivet connection, and bolt connection. In this embodiment, as shown in FIG. 6, the bottom protection plate 7 has mounting bosses 71 protruding toward the heat exchange plate 5 at positions corresponding to the reinforcing members 6. Each mounting boss 71 has a bolt hole, and the reinforcing member 6 is connected to the mounting boss 71 by a bolt. The mounting bosses 71 can reduce the mating area between the bottom protection plate and the reinforcing member 6, which reduces the difficulty of processing the entire bottom protection plate 7.

[0034] In this embodiment, the cells 20 of the cell assembly 2 are stacked in order in the width direction of the battery pack 100. Correspondingly, as shown in Figures 6 and 7, the pressure release through holes 51 of the heat exchange plate 5 are also arranged in order in the width direction of the battery pack 100. Since each base portion 61 is in the form of a long strip extending in the width direction of the battery pack 100, the base portion 61 can correspond to the pressure release through hole 51 in the width direction of the battery pack 100.

[0035] As shown in Figs. 14 to 18, in this embodiment, each support portion 62 is in the form of a long strip extending in the width direction of the battery pack 100. The support portions 62 are arranged on both sides of the base portion 61 in the length direction of the battery pack 100, and each pressure release through hole 51 is arranged between two support portions 62. Since each pressure release through hole 51 is arranged correspondingly between two support portions 62, the high-temperature, high-pressure material discharged from the pressure release through hole 51 can flow between the two support portions 62. The two support portions 62 can block the high-temperature, high-pressure material between the two support portions 62 and limit the discharge trajectory of the high-temperature, high-pressure material, thereby reducing damage to the battery pack structure outside the reinforcing member 6 caused by the high-temperature, high-pressure material.

[0036] Furthermore, in this embodiment, the cell assembly 2 and the heat exchange plate 5 are bonded via a structural adhesive and a thermally conductive adhesive. The structural adhesive and the thermally conductive adhesive are filled in the gap between the cell assembly 2 and the heat exchange plate 5, which is advantageous for blocking high-temperature and high-pressure substances. In this way, the risk of high-temperature and high-pressure substances leaking to other parts in the case 1 and causing a chain reaction of thermal runaway of the cells 20 is reduced.

[0037] In this embodiment, a lifting section 63 extending in the width direction of the battery pack 100 is further disposed on an edge of the support section 62 close to the heat exchange plate, and the lifting section 63 is attached to the heat exchange plate 5. The lifting section 63 increases the contact area between the support section 62 and the heat exchange plate 5, thereby reducing the extrusion stress between the support section 62 and the heat exchange plate 5 and improving the strength of the heat exchange plate 5.

[0038] More specifically, as shown in Fig. 14 to Fig. 17, in some embodiments, the two lifting portions 63 extend toward each other, that is, each lifting portion 63 is located between and connected to two support portions 62. A receiving through hole 60 corresponding to the pressure release through hole 51 is arranged in the lifting portion 63. Since each lifting portion 63 is located between the two support portions 62, the bending torque received by the reinforcing member 6 is reduced, and deformation of the reinforcing member 6 is prevented.

[0039] Specifically, in this embodiment, the reinforcing member 6 is a square tube extending in the width direction of the battery pack 100. In the height direction of the battery pack 100, the bottom of the square tube is the base portion 61, the outer walls on both sides of the bottom are the support portions 62, and the top of the square tube is the lift portion 63. Each receiving through hole 60 can also be opened sequentially at the top of the square tube along the length direction of the square tube by machining such as punching. In addition, since the square tube can be directly purchased according to the specifications without reopening the mold and processing, the manufacturing cost of the reinforcing member 6 can be reduced.

[0040] 14 and 15, in some embodiments, the number of receiving through holes 60 is less than the number of pressure relief through holes 51, and one of the receiving through holes 60 is arranged corresponding to a plurality of pressure relief through holes 51. By arranging one accommodating through hole 60 corresponding to a plurality of pressure relief through holes 51, the number of receiving through holes 60 can be reduced, and processing costs can be reduced.

[0041] 16 and 17, in other embodiments, the number of receiving through-holes 60 may also correspond to the number of pressure relief through-holes 51, and the receiving through-holes 60 and the pressure relief through-holes 51 are arranged in a one-to-one relationship. Compared with an arrangement of one receiving through-hole 60 corresponding to a plurality of pressure relief through-holes 51, the receiving through-holes 60 and the pressure relief through-holes 51 are arranged in a one-to-one relationship, so that the contact area between the reinforcing member 6 and the heat exchange plate 5 is increased. In this way, the lifting effect of the heat exchange plate 5 is improved and stress concentration is reduced.

[0042] As shown in Figs. 18 to 20, in some embodiments, the two lifting parts 63 extend away from each other, that is, the lifting part 63 is disposed on each of the two support parts 62. The lifting part 63 is located on one side of the corresponding support part 62, which is away from the other support part 62. Specifically, the lifting part 63 is a flange formed by bending the edge of the support part 62 close to the heat exchange plate 5 and extending toward the outside of the support part 62. The base part 61, the support part 62, and the lifting part 63 of the reinforcing member 6 may all be formed from plate material by a press processing process. The press processing process has the advantages of being simple, low cost, and high processing efficiency. In this embodiment, the included angle between the base part 61 and each support part 62 is an obtuse angle, so that the interval between the two support parts 62 is wide, and the high-temperature and high-pressure substance can be quickly discharged from the reinforcing member 6.

[0043] As shown in Figs. 2 to 7, in this embodiment, a plurality of cell assemblies 2 are arranged in the case 1, and the cell assemblies 2 are arranged in sequence in the longitudinal direction of the battery pack 100 on the heat exchange plate 5. A plurality of reinforcing members 6 are arranged in a line corresponding to the cell assemblies 2. By increasing the number of cell assemblies 2, the total energy storage capacity of the battery pack can be increased. By increasing the number of reinforcing members 6, the structural strength of the heat exchange plate 5 and the bottom protection plate 7 can be improved. Furthermore, since the reinforcing members 6 are arranged corresponding to the cell assemblies 2, the extrusion stress of the cell assemblies 2 on the heat exchange plate 5 is alleviated, and the heat exchange plate 5 is better supported.

[0044] As shown in FIG. 3 to FIG. 11, in this embodiment, a separation beam 9 extending in the width direction of the battery pack 100 is disposed on one side of the heat exchange plate 5 away from the bottom protective plate 7, and each separation beam 9 is located between two adjacent cell assemblies 2. In this embodiment, a separation beam 9 is disposed between adjacent battery cell assemblies 2 in the length direction of the battery pack 100. The separation beam 9 supports the outer wall of the case 1 along the width direction of the battery pack 100, and can improve the structural strength of the case 1. Furthermore, each separation beam may separate the cell assemblies 2 on both sides of the separation beam 9. When a cell 20 of one cell assembly 2 on one side of the separation beam 9 experiences thermal runaway, the separation beam 9 can block high-temperature and high-pressure materials and reduce the impact of the thermally runaway cell assembly 2 on the adjacent cell assembly 2.

[0045] 8 to 10, in this embodiment, both ends of each separation beam 9 are connected to the inner wall of the case 1, and a discharge through hole 12 is arranged in the outer wall of the case 1 corresponding to the end of the separation beam 9. A discharge passage 8 communicating with the discharge through hole 12 is arranged in the separation beam 9, and a communicating through hole 52 communicating with the discharge passage 8 is arranged in the heat exchange plate 5 corresponding to the separation beam 9. The heat exchange plate 5 and the bottom protection plate 7 communicate with the discharge through hole 12 via the communicating through hole 52 and the discharge passage 8.

[0046] After thermal runaway of the cell 20, the high-temperature and high-pressure material discharged between the heat exchange plate 5 and the bottom protective plate 7 flows into the discharge path 8 through the communicating through-hole 52, and is discharged to the outside of the battery pack 100 through the discharge path 8 and the discharge through-hole 12. Since the discharge path 8 is disposed within the separating beam 9, no additional arrangement space is required, the volume of the battery pack 100 is reduced, and the energy density of the battery pack 100 is increased.

[0047] In order to reduce the volume of the battery pack 100 and increase the energy density of the battery pack 100, the dimension between the heat exchange plate 5 and the bottom protection plate 7 in the height direction of the battery pack 100 is usually relatively narrow. Correspondingly, the dimension of the outer wall of the case 1 corresponding to the height direction of the battery pack 100 between the heat exchange plate 5 and the bottom protection plate 7 becomes narrow, making it difficult to arrange the discharge through hole 12. In this embodiment, the separation beam 9 is arranged on one side of the heat exchange plate 5 away from the bottom protection plate 7, so that the outer wall of the case 1 ensures sufficient arrangement space on one side of the heat exchange plate 5 away from the bottom protection plate 7 in the height direction of the battery pack 100. The discharge through hole 12 is arranged on the outer wall of the case 1 corresponding to the end of the separation beam 9 on one side of the heat exchange plate 5 away from the bottom protection plate 7. In this way, the arrangement space of the discharge through hole 12 is widened, the dimension of the discharge through hole 12 in the height direction of the battery pack 100 is increased, and the efficiency of discharging high-temperature and high-pressure substances is further improved.

[0048] As shown in Fig. 6 and Fig. 8 to Fig. 10, in this embodiment, the outer wall of the case 1 is a side beam 10 having a cylindrical structure formed by rolling high tensile steel material. The cylindrical structure has the advantage of being high strength and lightweight, and can improve the structural strength of the entire case 1. The end of the separation beam 9 communicates with the inside of the side beam 10. The discharge through hole 12 opens on one side of the side beam 10 close to the outside of the case 1, and the discharge passage 8 in the separation beam 9 communicates with the discharge through hole 12 via the side beam 10.

[0049] Specifically, as shown in FIGS. 6, 11, and 12, in the present embodiment, the separation beam 9 includes a top portion 91 extending in the width direction of the battery pack 100. The top portion is located on the heat exchange plate 5, and on both sides of the top portion, two side portions 92 are arranged toward the heat exchange plate 5. The side portions are connected to the heat exchange plate 5, and together with the heat exchange plate 5 and the top portion, they enclose to form the discharge passage 8. In the present embodiment, at the edge of each side portion 92, a flange for attaching to the heat exchange plate 5 is further arranged, which facilitates the attachment of the separation beam 9 and the heat exchange plate 5. The top portion 91, side portions 92, and flange of the separation beam 9 can be integrally press-formed from a sheet material, with a simple process and low cost. The side portion 92 of the separation beam 9 is connected onto the heat exchange plate 5. Since the side portion 92, top portion 91, and heat exchange plate 5 are closed to form the discharge passage 8, there is no need to provide an additional structure to form the discharge passage 8, which can reduce the weight of the battery pack 100 and the material cost.

[0050] As shown in FIGS. 1 to 10, in the present embodiment, a waterproof and moisture-permeable valve 11 is arranged in the discharge through-hole 12. The waterproof and moisture-permeable valve 11 opens when discharging high-temperature and high-pressure gas, so that the high-temperature and high-pressure substances in the case 1 can be discharged in a timely manner. The waterproof and moisture-permeable valve 11 closes before the high-temperature and high-pressure gas is discharged, has air permeability, and can prevent dust and other impurities outside the case 1 from entering the case 1 while balancing the pressure inside and outside the case 1. Thereby, the service life of the battery pack 100 can be improved.

[0051] In some embodiments, a protective layer 64 is arranged on one side of the base portion 61 of the reinforcing member 6 facing the pressure relief through-hole 51. In some other embodiments, the protective layer 64 is also arranged on one side of the support portion 62 of the reinforcing member 6 close to the base portion 61. By partially arranging the protective layer 64 on the reinforcing member 6, the arrangement area of the protective layer 64 can be reduced, and the weight and material cost of the battery pack 100 can be reduced.

[0052] 18 to 20, in this embodiment, the protective layer 64 is disposed on one side facing the pressure release through-hole 51 of the base portion 61 of the reinforcing member 6, and on one side of the support portion 62 close to the base portion 61. In this way, the protective range of the protective layer 64 is expanded, improving the protective effect of the reinforcing member 6. The protective layer 64 can reduce the impact, corrosion, and burn damage of the reinforcing member 6 due to high-temperature and high-pressure gas, further reducing the risk of the bottom protective plate 7 being penetrated by the high-temperature and high-pressure gas.

[0053] In some embodiments, the protective layer 64 may be a ceramic, silicate, phosphate, or other coating coated on the reinforcing member 6, and has high temperature resistance and certain structural strength, so that the protective layer 64 can reduce the impact and burnout of the reinforcing member 6 caused by high temperature and high pressure gas. As shown in FIG. 20, in this embodiment, the protective layer 64 is made of a mica plate 65. The mica plate 65 can be fixed to the reinforcing member 6 by gluing, bolting, etc., and has the advantages of being lightweight, high temperature resistance, excellent insulation, and high cost performance.

[0054] In this embodiment, the bottom protection plate 7 is made of aluminum, a composite material, a steel plate, or other materials, and the reinforcing member 6 may be made of aluminum or stainless steel. Aluminum is lightweight, which is advantageous for reducing the weight of the battery pack and improving the energy density of the battery pack. Stainless steel has excellent corrosion resistance and high strength, which is advantageous for improving the structural strength between the heat exchange plate 5 and the bottom protection plate 7.

[0055] In view of the above, in the battery pack provided by the present invention, the cell assemblies 2 are arranged on a heat exchange plate 5, and each cell assembly 2 includes a plurality of cells 20. The explosion-proof valves 4 of the cells 20 are all arranged on one side of the cells 20 facing the heat exchange plate 5, and the heat exchange plate is provided with pressure release through holes 51 corresponding to the explosion-proof valves 4. In this way, when the explosion-proof valve 4 of the cell 20 is opened, the high-temperature and high-pressure material ejected from the explosion-proof valve 4 can flow between the heat exchange plate 5 and the bottom protective plate 7 through the corresponding pressure relief hole 51 for pressure relief. In this way, when the explosion-proof valve 4 of the cell 20 is opened, the high-temperature and high-pressure material ejected from the explosion-proof valve 4 can flow between the heat exchange plate 5 and the bottom protective plate 7 through the corresponding pressure relief hole 51 for pressure relief. The reinforcing members 6 are disposed between the heat exchange plate 5 and the bottom protective plate 7, and each reinforcing member 6 includes a base portion 61 and a support portion 62 connected to the base portion 61. The base portion 61 is disposed on the bottom protective plate 7, and the support portion 62 is supported between the bottom protective plate 7 and the heat exchange plate 5. In the height direction of the battery pack, the projection of the pressure relief through hole 51 at least partially overlaps with the projection of the base portion 61. Thus, the reinforcing members 6 support and reinforce the bottom protective plate 7 and the heat exchange plate 5. Furthermore, after the high-temperature, high-pressure substance enters between the heat exchange plate 5 and the bottom protective plate 7 through the pressure release through-hole 51, the high-temperature, high-pressure substance can be blocked by the portion in the height direction of the battery pack 100 where the projection of the base portion 61 of the reinforcing member 6 overlaps with the projection of the pressure release through-hole 51. In this way, corrosion and direct effects of the high-temperature, high-pressure substance on the bottom protective plate 7 are reduced, and the risk of the bottom protective plate 7 being penetrated is also reduced.

[0056] The above-described embodiments are illustrative of the principles and effects of the present invention, and are not intended to limit the present invention. Those skilled in the art may modify or change the above-described embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those skilled in the art without departing from the spirit and technical ideas disclosed in the present invention are still intended to be included in the scope of the claims of the present invention. [Industrial Applicability]

[0057] The battery pack of the present invention can be applied in the field of battery technology. [Explanation of symbols]

[0058] 1: Roller 2: Axle fixing device 3: Bracket 4: Explosion-proof valve 5: Heat exchange plate 6: Reinforcement 7: Bottom protection plate 8: Exhaust channel 9: Separation beam 10: Side beam 11: Waterproof and breathable valve 12: Discharge through hole 20: Cell 51: Pressure relief hole 52: Communication through hole 53: Heat exchange channel 60: Receiving through hole 61: Base 62: Support part 63: Lifting section 64: Protective layer 65: Mica plate 71: Mounting boss 91: Top 92: Side 100: Battery pack

Claims

1. a case; and a cell assembly disposed within the case, the case including a heat exchange plate and a bottom protection plate disposed below the heat exchange plate, the cell assembly being disposed on the heat exchange plate; Each of the cell assemblies includes a plurality of cells, and an explosion-proof valve is arranged on one side of each of the cells facing the heat exchange plate, and a pressure relief through hole corresponding to the explosion-proof valve is arranged on the heat exchange plate; A battery pack, wherein a reinforcing member is arranged between the heat exchange plate and the bottom protective plate, each of the reinforcing members includes a base portion and a support portion connected to the base portion, the base portion is arranged on the bottom protective plate, the support portion is supported between the bottom protective plate and the heat exchange plate, and in the height direction of the battery pack, a projection of the pressure release through hole at least partially overlaps with a projection of the base portion.

2. 2. The battery pack according to claim 1, wherein the pressure release through-holes are arranged in sequence along a width direction of the battery pack, and each of the base portions is in the form of a long strip and extends along the width direction of the battery pack.

3. 3. The battery pack of claim 2, wherein each of the support portions is a long strip extending along a width direction of the battery pack, the support portions are arranged along both sides of the base portion in the length direction of the battery pack, and each of the pressure release through holes is arranged between two of the support portions.

4. 4. The battery pack according to claim 3, wherein a lifting portion extending along the width direction of the battery pack is further disposed on an edge of the support portion close to the heat exchange plate, the lifting portion being attached to the heat exchange plate.

5. The battery pack according to claim 4 , wherein the lifting sections are disposed on two of the support sections, and the two lifting sections extend away from each other.

6. The battery pack according to claim 5 , wherein an included angle between the base portion and each of the supports is an obtuse angle.

7. The battery pack according to claim 4 , wherein the two lifting portions extend toward each other, and the lifting portions have receiving through-holes arranged therein that correspond to the pressure release through-holes.

8. 8. The battery pack of claim 7, wherein the number of the receiving through holes is less than the number of the pressure relief through holes, and one of the receiving through holes is arranged to correspond to a plurality of the pressure relief through holes, or the number of the receiving through holes corresponds to the number of the pressure relief through holes, and the receiving through holes and the pressure relief through holes are arranged in a one-to-one relationship.

9. The battery pack according to any one of claims 1 to 8, wherein a plurality of the cell assemblies are arranged, the plurality of cell assemblies being arranged in sequence along the longitudinal direction of the battery pack on the heat exchange plate, and a plurality of the reinforcing members are arranged, the reinforcing members being arranged in sequence corresponding to the cell assemblies.

10. 10. The battery pack of claim 9, wherein a separation beam is disposed on one side of the heat exchange plate away from the bottom protection plate, the separation beam extending along the width direction of the battery pack, and each separation beam is located between two adjacent cell assemblies.

11. The battery pack of claim 10, wherein both ends of each of the separation beams are connected to an inner wall of the case, a discharge through hole is arranged in the outer wall of the case corresponding to the end of the separation beam, a discharge path communicating with the discharge through hole is arranged within the separation beam, a communicating through hole communicating with the discharge path is arranged on the heat exchange plate corresponding to the separation beam, and the heat exchange plate and the bottom protective plate are connected to the discharge through hole via the communicating through hole and the discharge path.

12. 12. The battery pack of claim 11, wherein each of the separation beams includes a top portion extending along a width direction of the battery pack, the top portion being located above the heat exchange plate, and two side portions being arranged on both sides of the top portion facing the heat exchange plate, the side portions being connected onto the heat exchange plate, and the side portions, the heat exchange plate and the top portion surroundingly form the exhaust passage.

13. The battery pack according to claim 11 , wherein a waterproof moisture permeable valve is disposed in the exhaust through hole.

14. The battery pack according to any one of claims 1 to 8, wherein a projection of the pressure release through hole is located within a projection of the base portion in a height direction of the battery pack.

15. The battery pack according to any one of claims 1 to 8, wherein a protective layer is disposed on at least one of the side of the base portion facing the pressure release through hole and the side of the support portion close to the base portion.

16. The battery pack according to claim 15 , wherein the protective layer is made of a mica plate.

17. The battery pack according to any one of claims 1 to 8, wherein the reinforcing member is made of stainless steel.

18. The battery pack according to any one of claims 1 to 8, wherein a heat exchange flow path for circulating a heat exchange medium is arranged in the heat exchange plate.

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